static extern uint GlobalGetAtomName(ushort nAtom, StringBuilder lpBuffer, int nSize);

Declare Function GlobalGetAtomName Lib "kernel32.dll" Alias "GlobalGetAtomNameA" ( _

static extern uint GlobalGetAtomName(ushort nAtom, StringBuilder lpBuffer, int nSize);

nSize = GlobalGetAtomName(AtomID, AtomName, nSize);